A wide variety of stent configurations and constructions are available for use with stented valves, such as stented heart valves. Many of these stents comprise wire or metal frames having a number of different components or sections that are arranged in a particular manner to provide certain characteristics for the finished device or component. For some applications, the stents can be made from shape memory materials, such as Nitinol, that can be compressed to a reduced size for implantation held in that compressed state, and then released to allow their expansion once they are positioned at a desired implantation site. In other applications, the stents can be compressed to a reduced size, and then expanded when desired through the use of an outward radial force that is applied from the inner area of the stent, such as can be accomplished with an expandable balloon. In still other applications, a stent used for a stented valve may not be compressible and expandable, but may instead have fixed dimensions. In many of these applications, the stents are provided with relatively cylindrical outer shapes to generally match the shape of the vessels in which they will be implanted.
One method of making a stent is to start with a tube or cylinder of material having solid walls and cutting out certain portions to provide apertures and/or other structural features for the stent. For example, removing large and/or multiple portions of material from a cylinder may be desirable to provide openings in certain areas of a stent while providing sufficient structure that will be conducive to compression for percutaneous delivery. However, it can be difficult to manufacture relatively large tubes that are made of materials such as Nitinol, and these tubes can therefore be expensive and difficult to find. Another method of making stents, such as stents having large diameters, is to use Nitinol wires arranged and attached to each other in predetermined patterns to make a particular structure. However, this method can be tedious and also requires crimping or welding wire ends to each other to form a cylinder, which can be very labor intensive. Yet another method of making stents involves using a flat sheet of material from which portions of material are removed. However, this method also requires the use of a weld seam to join the two ends of the flat sheet into a tubular stent. Although such constructions can be appropriate in some situations, it is also understood that weld seams can be the weakest point in a stented valve construction. Thus, it is desirable to provide additional methods for producing stents of various materials and may particularly be desirable to provide methods and configurations that do not require the use of welds or other attachment methods.